I hope no one is stressing you out! I think we are all just trying to be as helpful and thorough as possible. That aside, if you want to flush, flush the lines and condensor as well as possible. Flushing the evaporator can make a real mess, and I chose to just blow it out from one pipe while I held a rag on the other pipe. I stopped blowing when the rag no longer showed oil residue. Its small, so you only have trace amounts of oil.
Your other otion besides buying a vacuum pumps is simply to pay a shop to evacuate and charge the system once you have it all back together. I'm being objective: yes everyone sells them, but I have never heard anyone say they work well. And again, it is extremely important to get all the moisture out of the system, and that little thing just won't cut it.
Lastly, if you do pull vacuum yourself, do it on a hot day in direct sunlight, and drive the car first to get the engine compartment good and hot.
I hope it all goes well.